/** @file A non-functional instance of the Timer Library. Copyright (c) 2007 - 2023, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include #include #include #include #include #include #include /** Stalls the CPU for at least the given number of microseconds. Stalls the CPU for the number of microseconds specified by MicroSeconds. @param MicroSeconds The minimum number of microseconds to delay. @return The value of MicroSeconds inputted. **/ UINTN EFIAPI MicroSecondDelay ( IN UINTN MicroSeconds ) { return NanoSecondDelay (MicroSeconds * 1000); } /** Stalls the CPU for at least the given number of nanoseconds. Stalls the CPU for the number of nanoseconds specified by NanoSeconds. @param NanoSeconds The minimum number of nanoseconds to delay. @return The value of NanoSeconds inputted. **/ UINTN EFIAPI NanoSecondDelay ( IN UINTN NanoSeconds ) { EMU_THUNK_PPI *ThunkPpi; EFI_STATUS Status; EMU_THUNK_PROTOCOL *Thunk; // // Locate EmuThunkPpi for // Status = PeiServicesLocatePpi ( &gEmuThunkPpiGuid, 0, NULL, (VOID **)&ThunkPpi ); if (!EFI_ERROR (Status)) { Thunk = (EMU_THUNK_PROTOCOL *)ThunkPpi->Thunk (); Thunk->Sleep (NanoSeconds); return NanoSeconds; } return 0; } /** Retrieves the current value of a 64-bit free running performance counter. The counter can either count up by 1 or count down by 1. If the physical performance counter counts by a larger increment, then the counter values must be translated. The properties of the counter can be retrieved from GetPerformanceCounterProperties(). @return The current value of the free running performance counter. **/ UINT64 EFIAPI GetPerformanceCounter ( VOID ) { EMU_THUNK_PPI *ThunkPpi; EFI_STATUS Status; EMU_THUNK_PROTOCOL *Thunk; // // Locate EmuThunkPpi for // Status = PeiServicesLocatePpi ( &gEmuThunkPpiGuid, 0, NULL, (VOID **)&ThunkPpi ); if (!EFI_ERROR (Status)) { Thunk = (EMU_THUNK_PROTOCOL *)ThunkPpi->Thunk (); return Thunk->QueryPerformanceCounter (); } return 0; } /** Retrieves the 64-bit frequency in Hz and the range of performance counter values. If StartValue is not NULL, then the value that the performance counter starts with immediately after is it rolls over is returned in StartValue. If EndValue is not NULL, then the value that the performance counter end with immediately before it rolls over is returned in EndValue. The 64-bit frequency of the performance counter in Hz is always returned. If StartValue is less than EndValue, then the performance counter counts up. If StartValue is greater than EndValue, then the performance counter counts down. For example, a 64-bit free running counter that counts up would have a StartValue of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0. @param StartValue The value the performance counter starts with when it rolls over. @param EndValue The value that the performance counter ends with before it rolls over. @return The frequency in Hz. **/ UINT64 EFIAPI GetPerformanceCounterProperties ( OUT UINT64 *StartValue OPTIONAL, OUT UINT64 *EndValue OPTIONAL ) { EMU_THUNK_PPI *ThunkPpi; EFI_STATUS Status; EMU_THUNK_PROTOCOL *Thunk; // // Locate EmuThunkPpi for // Status = PeiServicesLocatePpi ( &gEmuThunkPpiGuid, 0, NULL, (VOID **)&ThunkPpi ); if (!EFI_ERROR (Status)) { if (StartValue != NULL) { *StartValue = 0ULL; } if (EndValue != NULL) { *EndValue = (UINT64)-1LL; } Thunk = (EMU_THUNK_PROTOCOL *)ThunkPpi->Thunk (); return Thunk->QueryPerformanceFrequency (); } return 0; } /** Converts elapsed ticks of performance counter to time in nanoseconds. This function converts the elapsed ticks of running performance counter to time value in unit of nanoseconds. @param Ticks The number of elapsed ticks of running performance counter. @return The elapsed time in nanoseconds. **/ UINT64 EFIAPI GetTimeInNanoSecond ( IN UINT64 Ticks ) { UINT64 Frequency; UINT64 NanoSeconds; UINT64 Remainder; INTN Shift; Frequency = GetPerformanceCounterProperties (NULL, NULL); // // Ticks // Time = --------- x 1,000,000,000 // Frequency // NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u); // // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit. // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34, // i.e. highest bit set in Remainder should <= 33. // Shift = MAX (0, HighBitSet64 (Remainder) - 33); Remainder = RShiftU64 (Remainder, (UINTN)Shift); Frequency = RShiftU64 (Frequency, (UINTN)Shift); NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL); return NanoSeconds; }